Method, computer readable medium and apparatus for accessing a defect knowledge library of a defect source identification system

ABSTRACT

A method, computer readable medium and apparatus comprising a defect knowledge library (DKL), subscriber equipment and a communications network that connects the subscriber equipment t the DKL. The DKL contains a partitioned database of defect, defect source and defect mitigation information that is arranged by participating integrated circuit fabricator (referred to herein as a subscriber). The subscribers can identify the amount and type of information that they wish to share with other subscribers and whether their identity will be disclosed. The subscribers may share the data with specific “partners” or with other departments within their company, without sharing with other subscribers. The DKL system administrator charges a fee for the access rights. The more information that a subscriber shares with other subscribers, the lower the access fee. As such, subscribers are given financial incentive to share their information with other subscribers. Additionally, if a subscriber shares with others, then the other subscriber&#39;s data is made available to the sharing subscriber. As such, by sharing data, a particular subscriber has access to an expended library of DSI data without the need to accumulate the data themselves.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims benefit of United States provisionalpatent application Ser. No. 60/240,631, filed Oct. 16, 2000, which isherein incorporated by reference. This application contains subjectmatter that is related to the subject matter described in U.S. patentapplication Ser. Nos. ______, ______, and ______, (Attorney dockets 4744FET/MDR, 4747 FET/MDR, and 4748 FET/MDR), filed simultaneously herewith,which are each incorporated herein by reference in their entireties.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] This application claims the benefit of U.S. ProvisionalApplication No. 60/240,631 filed on Oct. 17, 2000, which is hereinincorporated by reference.

[0004] The present invention relates to semiconductor wafer processingsystems and, more particularly, the invention relates to systems thatidentify the source of defects for semiconductor wafers as the wafersare processed in a semiconductor wafer processing system.

[0005] 2. Background of the Related Art

[0006] Semiconductor wafers are prone to defects that occur duringprocessing. Defects may occur at any stage of the processing of thewafers as integrated circuits are formed thereupon. Generally eachfabricator of integrated circuits maintains a database of the causes ofdefects that occur on a regular basis. If the defect occurs often and asolution is apparent, the database may contain a correlation between thedefect, the defect's cause and the solution to the defect. For example,certain defects may occur when a particular chamber becomes dirty. Whenthese defects occur, the database would indicate the solution to be toexecute a cleaning cycle for the particular chamber.

[0007] The various integrated circuit fabricators develop their own,proprietary databases of defect information. As such, substantial fundsare expended to produce the databases over time.

[0008] Therefore, there is a need in the art for a method for poolingthe confidential defect information of multiple integrated circuitfabricators and anonymously sharing the defect information amongst theintegrated circuit fabricators. Such sharing of information wouldsubstantially reduce the amount of resources consumed in preparing thedefect source identification database.

SUMMARY OF THE INVENTION

[0009] The present invention is a method of accessing defect sourceidentification data from multiple integrated circuit manufacturers(database subscribers), fairly compensating the participants for theirefforts, and anonymously sharing the data amongst the participants in amanner that protects confidential information. Subscribers that do notshare information (non-participants) may also access the defect data fora fee.

[0010] More specifically, the defect source identification (DSI) systemcomprises a defect knowledge library (DKL), subscriber equipment and acommunications network that connects the subscriber equipment to theDKL. The DKL contains a partitioned database of defect, defect sourceand defect mitigation information that is arranged by participatingintegrated circuit fabricator (referred to herein as a subscriber). Thesubscribers can identify the amount and type of information that theywish to share with other subscribers and whether their identity will bedisclosed. The subscribers may share the data with specific “partners”or with other departments within their company, without sharing withother subscribers. The DKL system administrator charges a fee for theaccess rights. The more information that a subscriber shares with othersubscribers, the lower the access fee. As such, subscribers are givenfinancial incentive to share their information with other subscribers.Additionally, if a subscriber shares with others, then the othersubscriber's data is made available to the sharing subscriber. As such,by sharing data, a particular subscriber has access to an expendedlibrary of DSI data without the need to accumulate the data themselves.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] So that the manner in which the above recited features,advantages and objects of the present invention are attained and can beunderstood in detail, a more particular description of the invention,briefly summarized above, may be had by reference to the embodimentsthereof which are illustrated in the appended drawings.

[0012] It is to be noted, however, that the appended drawings illustrateonly typical embodiments of this invention and are therefore not to beconsidered limiting of its scope, for the invention may admit to otherequally effective embodiments.

[0013]FIG. 1 depicts an illustrative defect source identification (DSI)system that uses the method of the present invention;

[0014]FIG. 2 depicts a flow diagram of a setup method for the system ofFIG. 1; and

[0015]FIG. 3 depicts a flow diagram of a method of accessing informationin the system of FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0016] The present invention is a method for accessing a defectknowledge library (DKL) of a defect source identification (DSI) system.The DKL stores defect related information from a plurality of DKLsubscribers. The access control for each subscriber is facilitated bysetting access pricing and access levels, where the access pricing isthe price paid by a subscriber to access the information in the DKL andthe access level is the amount of information that the subscriber isallowed to access within the DKL. The access pricing and level dependsupon the amount of information that the subscriber shares with othersubscribers.

[0017]FIG. 1 is a block diagram of a DSI system 100 that utilizes themethod of the present invention. The DSI system 100 comprises DKL 102, acommunications network 104 and a plurality of subscriber equipment 106₁, 106 ₂ through 106 _(n) (together referred to as subscriber equipment106, where n is an integer greater than zero). The DKL 102 comprises adatabase 108 (physically stored in a computer memory) and a servercomputer 110. The server computer 110 comprises a central processingunit (CPU) 118, memory 120 and well-known support circuits 122. The CPU118 may be any one of the available computer processors that areavailable. The memory 120 may be random access memory, read only memory,disk drive storage, removable storage, or any combination of thesememory devices. As described with respect to FIGS. 2 and 3, the memory120 stores the software 124 that, when executed by the CPU 118, embodiesthe methods of the present invention. The support circuits 122 comprisewell-known circuits and devices including, but not limited to, cache,power supplies, clocks, network interface cards, input-output circuits,and the like.

[0018] The subscriber equipment 106 comprises a client computer 112 _(n)and a local database 114 _(n). The client computer 112 _(n) has asimilar physical structure as that of the server computer, i.e., a CPU,memory and support circuits. For clarity, these well known elements arenot specifically depicted.

[0019] The server computer 110 operates as a conventional “server”computer and the client computer operates as a conventional “client”computer such that a server-client relationship is formed between theDKL 102 and the subscriber equipment 106. In this manner, the database108 of defect data forms a relational database that receives informationfrom the client computer 112. The communications network 104 couples theDKL 102 to the subscriber equipment 106. The communications network maybe an ETHERNET local area network, (LAN), a token ring LAN, an INTERNETbased wide area network (WAN), a virtual private network, or acombination of these commonly used network topologies. Generally, anyform of communications network that enables the client and servercomputers to communicate with one another is sufficient for practicingthe present invention.

[0020] The client computer 110 operates to collect defect, defectsource, and defect mitigation data from a semiconductor wafer processingsystem 116 _(n). The system 116 _(n) is coupled to the subscriberequipment 106. The semiconductor wafer processing system 100 containsone or more metrology chambers or stations within which defect anddefect source information is generated. The local database 114 _(n)stores this defect and defect source data. The information from theclient database 114, either all or a subset thereof, is communicated tothe DKL 102 via the network 104. The subscriber controls the specificamount of data that is communicated to the DKL 102. A distributed defectsource analysis system such as the one depicted in FIG. 1 is disclosedin U.S. patent application Ser. No. ______, filed simultaneouslyherewith, (Attorney Docket 4748) and incorporated herein by reference inits entirety.

[0021] Some or all of the local database information is communicated tothe DKL database 108 where the DKL database is updated with all of thesubscriber's information. Each subscriber has access to a specificpartition of the database 110, e.g., partitions P₁, P₂ through P_(n).The database 110 stores defect data, defect source identification data,and defect mitigation information in each partition. As such, a commondatabase can be accessed by the subscribers to find solutions for theirdefects. For example, the subscriber may be having the same defect occurwithin their semiconductor wafer processing system. The systemadministrator may have a solution to the defect and make that solutionavailable. The subscriber can be given access to a common partition,e.g., partition C, where all subscribers can access various defectanalysis tools and information that are supplied by the systemadministrator.

[0022] The present invention concerns a method of charging for access tothe database 110 in a tiered manner depending upon a subscriber'swillingness to share defect information with other subscribers.Specifically, subscribers are provided different pricing levels andaccess levels depending on the level of sharing that the subscriberauthorizes.

[0023]FIG. 2 is a flow diagram of an account setup method 200 for thesystem 100 of FIG. 1. The method 200 is embodied in a software routinethat is stored in the server computer memory and, when the CPU executesthe software, causes the system to operate in a manner that is outlinedby the method 200.

[0024] The method begins at step 202 and proceeds to step 204 whereinthe subscriber sets up an account on the server computer. Within thesetup process, the subscriber is supplied with passwords and useridentification codes that correspond to their level of access. In step206, the subscriber identifies the level of sharing that they will allowfor their defect information. This sharing level varies from none toall. For example, some subscribers may not share any of their data withother subscribers. Other subscribers may share all of their defect data,but none of their defect mitigation information or defect sourceidentification data. Others may enable other subscribers to access allthe data that the subscriber supplies to the database withoutrestriction. Subscribers may also request certain data only be madeavailable to “partners” or affiliated companies that are alsosubscribers.

[0025] At step 208, the method 200 establishes an access level that iscommensurate with the sharing level, i.e., the subscriber is permittedaccess to other subscriber's defect data in the same degree that theypermit access to their data. The system may enable a subscriber to “buyup” such that they can share at one level and access at a higher levelby paying a higher price for the enhanced access.

[0026] At step 210, the method 200 sets the access price based upon theaccess level and sharing level. Generally, the more a subscriber shares,the less expensive the access price. The intent is to provide anincentive to subscribers to share defect information with othersubscribers. The pricing can be an access fee, where the subscriber ischarged for each use of the server, or as a monthly fee, where thesubscriber may access the server as much as desired for a flat monthlyrate.

[0027] The system administrator ensures that specific products andsubscriber names are not made available to the other subscribers. Assuch, the defect information that is shared is available on an anonymousbasis and does not contain confidential information. The point is toshare defect data, defect source identification and defect mitigationinformation amongst subscribers without compromising the trade secretsof any of the subscribers. Additionally, the subscriber posts much ofthe information such that the subscriber directly controls whatinformation will be shared. As such, the confidential information can beextracted from the posted information. Such sharing of informationenables all subscribers to benefit from the defect research performed bythe subscriber base as well as the system administrator. The method 200steps at step 212.

[0028]FIG. 3 is a flow diagram of a method 300 of fulfilling atransaction using the system of FIG. 1. The method 300 is embodied in asoftware routine that is stored in the server computer memory and, whenthe CPU executes the software, causes the system to operate in a mannerthat is outlined by the method 300.

[0029] The method 300 begins at step 302 and proceeds to step 304wherein the subscriber logs into the server computer through aninterface on the client computer. The interface is generally a graphicaluser interface (GUI) that enables the subscriber to enter the userid andpassword. Assuming the correct userid and passwords are provided, themethod proceeds to step 306 where access to the serve is granted. Ifincorrect userid or passwords are provided, the step 304 will invokeconventional error handling routines to request re-entry of the logininformation or block access to the system at step 308.

[0030] Once access is provided, at step 308, the subscriber may accessthe defect analysis tools of the DKL. These tools enable the subscriberto use an image based analysis suite that performs comparisons of thedefects experienced by the subscriber to a defect database. Once thedefects have been categorized, they are analyzed to identify the sourceof the defects. The source can then be used to determine certain defectmitigation techniques to be used to eliminate the defect. Suchmitigation techniques may pinpoint certain chambers in the waferprocessing system that may need cleaning, certain gases that arecontaminated, certain operating parameters of the processing system thatneed adjustment, and so on. If the subscriber has a high access level,then the analysis tools will use the subscriber's own data plus the dataof other subscribers and the system administrator to analyze the defectdata. As such, the subscriber has access to a substantial amount ofdefect information to draw from to determine the source and mitigationtechniques for specific defects. If new techniques are developed duringthe analysis session, they are stored in the database.

[0031] At step 310, a billing database is updated with information thatthe subscriber has accessed the database. The information that isupdated depends upon the subscriber's billing arrangement. For example,if the subscriber is on a use based pricing plan, then the update mustcontain the duration of the connection and the type of information andtools that were accessed. For monthly subscription type pricing, theupdate would only require basic subscriber data to identify whichsubscriber had accessed the DKL. The system administrator may wish thebilling database to contain other statistical information so the systemutilization statistics can be accumulated. At the end of the session,the method 300 logs out the subscriber and stops at step 312

[0032] Access to the DKL may be automated such that the subscriberequipment automatically connects to the DKL, supplies defect data,performs an analysis, retrieves the defect mitigation solution, andapplies the solution to the semiconductor wafer processing system thatis coupled to the subscriber equipment. The only time a person would benotified is if a solution to correct the defect is not readily availablefrom the database.

[0033] While foregoing is directed to the preferred embodiment of thepresent invention, other and further embodiments of the invention may bedevised without departing from the basic scope thereof, and the scopethereof is determined by the claims that follow.

1. A method for accessing a defect knowledge library of a defect sourceidentification system comprising: supplying information to the defectknowledge library from a plurality of subscribers, where a particularsubscriber establishes a data sharing level that defines an amount ofthe information that is supplied that can be shared with othersubscribers; and establishing, for the particular subscriber, an accessprice and an access level for accessing the defect knowledge librarythat is based upon a data sharing level of that particular subscriber.2. The method of claim 1 wherein at least one of the plurality ofsubscribers is an integrated circuit manufacturer.
 3. The method ofclaim 1 wherein the information comprises one or more of defect data,defect source data, defect mitigation information.
 4. The method ofclaim 1 wherein the access price for the particular subscriber isdecreased when the particular subscriber authorizes sharing of theirinformation with other subscribers, where the more information that isshared correspondingly reduces the access price.
 5. The method of claim1 wherein the access level controls the amount of information theparticular subscriber can access of other subscribers, where the higherthe access level the more information that the particular subscriber canaccess.
 6. The method of claim 5 wherein the access level for theparticular subscriber is increased when the particular subscriberauthorizes sharing of their information with other subscribers, wherethe more information that is shared correspondingly increases the accesslevel.
 7. A computer readable medium containing a software routine that,when executed by a processor, causes a system to perform a method foraccessing a defect knowledge library of a defect source identificationsystem, the method comprises: supplying information to the defectknowledge library from a plurality of subscribers, where a particularsubscriber establishes a data sharing level that defines an amount ofthe information that is supplied that can be shared with othersubscribers; and establishing, for the particular subscriber, an accessprice and an access level for accessing the defect knowledge librarythat is based upon a data sharing level of that particular subscriber.8. The method of claim 7 wherein at least one of the plurality ofsubscribers is an integrated circuit manufacturer.
 9. The method ofclaim 7 wherein the information comprises one or more of defect data,defect source data, defect mitigation information.
 10. The method ofclaim 7 wherein the access price for the particular subscriber isdecreased when the particular subscriber authorizes sharing of theirinformation with other subscribers, where the more information that isshared correspondingly reduces the access price.
 11. The method of claim7 wherein the access level controls the amount of information theparticular subscriber can access of other subscribers, where the higherthe access level the more information that the particular subscriber canaccess.
 12. The method of claim 11 wherein the access level for theparticular subscriber is increased when the particular subscriberauthorizes sharing of their information with other subscribers, wherethe more information that is shared correspondingly increases the accesslevel.
 13. Apparatus for accessing a defect knowledge library of adefect source identification system comprising: subscriber equipment forsupplying information to the defect knowledge library from a pluralityof subscribers, where a particular subscriber establishes a data sharinglevel that defines an amount of the information that is supplied thatcan be shared with other subscribers; and a server computer within thedefect knowledge library for establishing, for the particularsubscriber, an access price and an access level for accessing the defectknowledge library that is based upon a data sharing level of thatparticular subscriber.
 14. The apparatus of claim 13 wherein at leastone of the plurality of subscribers is an integrated circuitmanufacturer.
 15. The apparatus of claim 13 wherein the informationcomprises one or more of defect data, defect source data, defectmitigation information.
 16. The apparatus of claim 15 wherein the accessprice for the particular subscriber is decreased when the particularsubscriber authorizes sharing of their information with othersubscribers, where the more information that is shared correspondinglyreduces the access price.
 17. The apparatus of claim 1 wherein theaccess level controls the amount of information the particularsubscriber can access of other subscribers, where the higher the accesslevel the more information that the particular subscriber can access.18. The method of claim 17 wherein the access level for the particularsubscriber is increased when the particular subscriber authorizessharing of their information with other subscribers, where the moreinformation that is shared correspondingly increases the access level.